The present invention relates in general to a hybrid dental implant system and more particularly, to such a hybrid dental implant system constructed and arranged to facilitate the recreation of a dentition in patients by possessing the ability to freely interconvert from both a fixed and retentive (nonstress bearing) implant modality.
During mastication, teeth are subjected to an infinite number for foce vectors. Most of these forces are directed in an incisio-apical direction, i.e., cusp tip to root tip, but some forces are directed the other way, i.e., apico-incisal. These latter forces tend to dislodge full and removable partial dentures, thereby presenting a continual problem to the patient and dentist. In this regard, dental implants were created to help the dentist most naturally recreate a dentition in patients who had lost some or all of their teeth. These implants, in specific cases, have superseded full and removable partial dentures. The dental implant disclosed is an endosseous basket placed into a surgically prepared site in the jawbone. A prosthesis is then attached to that portion of the implant that extends through the soft gum tissue into the patient's mouth. One such dental implant is illustrated in U.S. Pat. No. 4,359,318 in the name of Neal Gittleman.
In general, these implants have been constructed in a variety of forms for use by the dentist, either as a fixed implant or as a retentive implant. The fixed implant, used for crown and bridge support, is generally preferred by dentists as it aids in restoring a more natural dentition. In the dentate patient chewing forces are absorbed in part by the resilient action of the bone and periodontal ligament, while a fixed implant loads the bone directly.
The retentive implant, on the other hand, is designed to retain a prosthesis, not support it as in the case of the fixed implant. The retentive design prevents dislodgement of the prosthesis when it is subjected to apico-incisal forces, yet minimizes the occlusal forces placed upon the implant by allowing the soft gum tissue to absorb most of the inciso-apical forces. The retentive implant combines the desirable aspects of full and removable partial dentures with those of an endosseous fixed dental implant. For example, the retentive implant overcomes the problem encountered with full and removable partial dentures by resisting dislodging forces. The prosthesis, connected to the jawbone via the implant, has a limited movement when subjected to apico-incisal forces. As a result, forces which can cause movement of the implant within bone will be maintained. This will manifest itself in a lower rate of peri-implant epithelialization, peri-implant infection, and implant failure.
In the event of failure of a fixed implant and/or natural abutment, it is often desirable that a retentive implant securing a denture be utilized. Furthermore, fixed implant modalities often do not lend themselves to be easily converted for use as a retentive implant. Therefore, it may be required that the dentist remove the prosthesis and fixed implant, in order that a retentive modality be substituted for retaining a full or partial denture. This procedure may subject both the patient and dentist to increased chair time, additional surgery, and further expenses.